Living World

• location


  20 to 30 degrees North and South of the Equator

  
• Average annual rainfall


  250mm
• diurnal temperature range


  may exceed 35 degrees
• soils


  sandy, rocky, around 1 metre deep, little organic content
• Three environmental challenges


  dry conditions, high temperatures, short periods of rainfall
• xerophytes


  plants that can survive in very dry conditions

  
• succulents


  plants that store water in their tissues e.g. cacti

  
• adaptations of a Kangaroo rat

  live underground in the day, produce little urine

  
• adaptations of an Acacia tree


  short trunks, fire -resistant, deep roots
• adaptations of a desert fox


  thick fur on soles of feet, light fur on body
• Interdependence between plants and soil and climate


  vegetation stabilises sandy soils and stops it being blown away
• Interdependence between animals and plants and climate

  animals eat plants that have gained nutrients from soil and water
• Mineral extract in the Western Desert

  Uranium mining near the Grand Canyon, Copper mining in the Sonoran Desert near Ajo.
• Examples of Farming in the Western Desert


  Lush crops of vegetables, peppers, grapes in the Coachella Valley, California.
• Aquifer


  a large store of underground water where a layer of permeable rock lies on top of impermeable rock.

  
• Examples of Energy in the Western Desert

  The Sonoran Solar Project in Arizona, The Navajo Nation Oil and Gas Company is worth $50m.
• Examples of Tourism in the Western Desert

  The Grand Canyon, the culture and heritage of the Navajo Indians, the entertainment industry in Las Vegas.
• The USA's Western Deserts

  Mojave, Sonoran and Chihuahuan Desert
• three challenges of the Western Desert

  Extreme temps, water supply, inaccessibility
• How have people adapted homes to extreme climate

  flat roofs to collect water, small windows to reduce sunlight and keep temperatures low inside, whitewashed walls to reflect sunlight
• How have people adapted to water shortages

  artificial grass, using drought-resistant garden plants, flat roofs to collect water, building dams
• How have people adapted to inaccessibility

  railways were built and then better roads and finally airports e.g. Las Vegas airport.
• desertification


  the process by which land becomes drier and degraded as a result of climate change, human activity or both
• human factors in desertification

  population growth, use of fuel wood, overgrazing, over-cultivation and soil erosion.
• Appropriate technology


  technology suited to the needs, skills, knowledge and wealth of local people. Usually combines simple ideas with inexpensive and available materials and is environmentally friendly
• Upesi Stove


  a locally made stove using readily available clay which is free. Uses much smaller amounts of wood so reduces need for fuelwood.
• Bunds


  low stone walls in parallel to the slope gradient, help prevent soil erosion and slow down the flow of rainwater helping it to soak into the soil
• The Green Wall


  A project to plant a wall of trees across the Sahel region. Tree roots help stabilise soil and leaves add to nutrient layer.
• Abiotic


  Relating to non-living things.

  
• Biotic


  The living elements of the ecosystem

  
• Biotic


  plants and animals

  
• Abiotic


  soil, rocks, water , climate

  
• Consumer


  Creature that eats herbivores and/or plant matter.

  
• Herbivore


  Creature that eats plant matter only

  
• Primary Consumer


  creature that eats only plant matter

  
• Decomposer


  An organism such as a bacterium or fungus, that breaks down dead tissue, which is then recycled to the environment.

  
• Ecosystem


  A community of plants and animals that interact with each other and their physical environment.

  
• Food chain


  The connections between different organisms (plants and animals) that rely on one another as their source of food.

  
• Food Web


  A complex hierarchy of plants and animals relying on each other for food.

  
• Nutrient Cycle


  A set of processes whereby organisms extract minerals necessary for growth from soil or water, before passing them on through the food chain - and ultimately back to the soil and water.